National Repository of Grey Literature 20 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Analysis of biotic matrices by Laser-Induced Breakdown Spectroscopy
Střítežská, Sára ; Karel,, Novotný (referee) ; Modlitbová, Pavlína (advisor)
This bachelor thesis discusses the possibility of using Laser-induced breakdown spectroscopy (LIBS) for biological application. The LIBS method was used to determine spatial distribution of a chosen element, cadmium, in selected model plant, white mustard (Sinapis Alba L.) The exposure took place in hydroponic conditions and lasted for 72 hours, therefore it was an acute toxicity test. Three different sources of cadmium were tested, mercaptopropionic acid stabilized quantum dots (CdTe QDs), silica coated quantum dots (CdTe/SiO2 QDs), and cadmium chloride, which was used as a positive control. After the exposure and before determination of the spatial distribution of cadmium in plants, a significant portion of the thesis was devoted to optimization of selected parameters of LIBS measurement (laser energy and gate delay). Subsequently, the cadmium distribution was determined and the obtained results were discussed with regards to the tested substance, its stability and its tendency to aggregate/agglomerate in water medium in contact with testing organism during exposure. In the final part of the work, the suitability of the LIBS method for the determination of spatial distribution of chosen contaminants was evaluated.
Slovak population of Prague
Martinák, Matej ; Ouředníček, Martin (advisor) ; Svoboda, Peter (referee)
Despite its large size and historically specific position, the Slovak population of Prague and Czechia remains relatively understudied. The aim of this bachelor's thesis is to review the history and the present of Slovaks in Prague in terms of their number and statistical records, demographic and social structure, and distribution within the city. By analyzing current and historical statistical data, an overview of the evolution of Slovak migration to Prague and of the number of Slovaks in Prague has been conducted and problems regarding data records have been clarified. Based on detailed data from the Czech statistical office an overview of the demographic and social structure of Slovaks in Prague and comparison with some relevant populations was carried out. The level of concentration was analyzed by cartographic outputs. By its broad conception of the topic, the bachelor thesis broadens the existing knowledge about one of the largest ethnic groups in the capital of Czechia. Keywords: Slovaks; Prague; urban processes; migration; social structure; spatial distribution
Research methods of precipitation spatial and temporal distribution, their using and results in the Czech Republic
JINDROVÁ, Eliška
This bachelor thesis has the character of a literature research, deals with the topic of temporal and spatial distribution of precipitation and methods of their evaluation. It begins with a description of the formation of precipitation and their division. The next chapter is devoted to the factors that affect the distribution of precipitation and the course of precipitation. Following with a description of ground and distance methods of measuring precipitation. This thesis also deals with the analysis of time series and description of methods of spatial distribution of precipitation. With the help of expert articles and studies from the Czech Republic, several examples of different precipitation distributions are presented. At conclusion of this thesis is a comparison of the results of different methods.
Changes in pollinator behaviour under different plant spatial aggregation
Štenc, Jakub ; Janovský, Zdeněk (advisor) ; Bartoš, Michael (referee)
Plants often occur aggregated into clusters and this spatial pattern is supposed to affect pollinator behaviour and pollen dispersal. Such pollinator reaction may influence reproductive success of zoogamous plant species both in terms of number of available mates and their genetic diversity (nearby growing plant individuals are also often closely related, especially in clonal plants). In the present thesis, I investigated the influence of plant spatial aggregation on pollinator behaviour and how this translates into pollen transfer. For that purpose, I carried three experiments. In the Experiment 1, I used potted plants placed into arrays and aggregated into four patches in order to track the pollen dispersal by means of a UV-dye pollen analogue. I manipulated distances between plants within clusters (dense × loose) and between clusters (near × far). I conducted this experiment for three plant species differing in their pollinator spectra. In the Experiment 2, I observed pollinator foraging sequences (sequences of visited plant individuals) under the same experimental design as for the first experiment, but I carried out this experiment for five plant species. In addition in one study species, Dianthus carthusianorum, I conducted the Experiment 3 to get better insight into pollination effectiveness...
Spatial distribution of the European catfish Silurus glanis influenced by familiarity
Fořt, Martin ; Slavík, Ondřej (advisor) ; Kozák, Pavel (referee)
One of the key elements of animal social behaviour is the recognition of individuals on the basis of previous experience. This relationship is called familiarity and affects individual's behaviour. We know many examples of familiarity-based behaviour among fish. Many results show that familiarity is advantageous. Familiar individuals are less aggressive, forage more, make more cohesive shoals and grow faster. We tested the influence of the familiarity on the spatial distribution of juvenile wels catfish Silurus glanis from two unfamiliar groups, which were held in separate tanks. In a laboratory experiment was the spatial distribution of individuals monitored in the artificial stream by using passive integrated transponders. Shelters, which were occupied by individuals, were placed in the stream. Two groups of fish were subsequently added into the experiment under conditions of limited or unlimited shelters. These groups came from the same tank (so they were familiar) or from different tanks (so they were unfamiliar). 1080 individuals were used in this experiment and over three million individual fish positions were recorded. We discovered changing levels of activity under different conditions. When we compared activity of original and additional individuals, we measured higher level of activity in...
Spatial analysis of Airbnb apartment locations in Prague
Kroutil, Filip ; Pertold-Gebicka, Barbara (advisor) ; Nevrla, Matěj (referee)
This paper investigates the determinants of the spatial distribution of Airbnb listings in Prague, the capital city of the Czech Republic, and compares it with the distribution of traditional accommodation units such as hotels. The analysis is based on two datasets, one containing all 14 864 Airbnb listings in Prague in November 2019 and the other including a snapshot of 864 hotels from March 2020. Local indicators of spatial association and traditional OLS regression were used to study the determinants and differences between the distributions. The results show a simpler and more centered distribution in the case of Airbnb units. The study also provides a model describing Airbnb density in each municipal district with high predicting power. Insights from this thesis could help understand the principles behind Airbnb dispersion and so create a basis for future regulations of this relatively new market segment.
The importance of water sources for space-use of mammals in African savannah
Homoláč, David ; Hořák, David (advisor) ; Brandlová, Karolína (referee)
African savannas are seasonal ecosystems experiencing a significant dry period each year. During the dry season, water scarcity has both, spatial and temporal consequences on the movements of large mammals. Some mammals can cope with these resource restrictions better than others. These water independent mammals predominantly feed on browse (giraffe, kudu, eland) and can be found further from water sources. However, these mammals can utilize areas near rivers as these areas provide food resources. Water dependent species are predominantly grazers and non-ruminants (zebra, wildebeest, elephant). Water shortage during a dry season restricts the movements of these species, which can be generally found in the vicinity of water bodies. Carnivore species (lions) react on the spatial restrictions of ungulates by adjusting their hunting areas to the vicinity of water sources. Both intra-guild (African wild dog) and inter-gild prey species (ungulates) develop anti-predatory strategies such as temporal and spatial segregation. African wild dogs use dens far from water points and ungulate species use to drink during daytime when lions are not active. Spatial and temporal segregation are also strategies to cope with competitors. Daily patterns of water point visitations can vary suggesting other factors...
Changes in pollinator behaviour under different plant spatial aggregation
Štenc, Jakub ; Janovský, Zdeněk (advisor) ; Bartoš, Michael (referee)
Plants often occur aggregated into clusters and this spatial pattern is supposed to affect pollinator behaviour and pollen dispersal. Such pollinator reaction may influence reproductive success of zoogamous plant species both in terms of number of available mates and their genetic diversity (nearby growing plant individuals are also often closely related, especially in clonal plants). In the present thesis, I investigated the influence of plant spatial aggregation on pollinator behaviour and how this translates into pollen transfer. For that purpose, I carried three experiments. In the Experiment 1, I used potted plants placed into arrays and aggregated into four patches in order to track the pollen dispersal by means of a UV-dye pollen analogue. I manipulated distances between plants within clusters (dense × loose) and between clusters (near × far). I conducted this experiment for three plant species differing in their pollinator spectra. In the Experiment 2, I observed pollinator foraging sequences (sequences of visited plant individuals) under the same experimental design as for the first experiment, but I carried out this experiment for five plant species. In addition in one study species, Dianthus carthusianorum, I conducted the Experiment 3 to get better insight into pollination effectiveness...
Usefulness of habitat suitability models in research of orchid spatial distribution
Linyucheva, Anastasia ; Kindlmann, Pavel (advisor) ; Šímová, Irena (referee)
The subject of this thesis is to summarise information about use of the habitat suitability models with a focus on orchids modelling. Habitat suitability modelling is used to study the relationship between the occurrence of the species and the environmental factors of its habitat. Modelling orchid species is especially useful for modelling of rare and endangered species, it can accurately predict the occurrence of different species under future climatic conditions and in non-native localities. Appearance of mycorrhizal symbiotic fungi is a specific factor affecting distribution of most orchids, but it is very problematic to include it in modelling. Also, there is an uncertainty about an impact of this factor on orchid distribution. Results of different modelling methods are sometimes controversial, this issue is studied, but there are no such studies in orchids modelling. Keywords: Orchids, spatial distribution, models, distribution, prediction

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